Description: A ring homomorphism is a homomorphism of multiplicative monoids. (Contributed by Stefan O'Rear, 7-Mar-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | isrhm.m | ||
| isrhm.n | |||
| Assertion | rhmmhm |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | isrhm.m | ||
| 2 | isrhm.n | ||
| 3 | 1 2 | isrhm | |
| 4 | 3 | simprbi | |
| 5 | 4 | simprd |